Do not decompress on one finding alone

Time-limited draft: OCEMS circulated a June 2026 redline revision with phased implementation beginning October 1, 2026 and final implementation April 1, 2027. This guide summarizes the versions still listed on the current OCEMS procedure index as of September 16, 2026 and must be re-reviewed before that rollout.
For adults/adolescents, absent breath sounds or shortness of breath alone are not sufficient. The suspected tension-pneumothorax findings must be associated with hypoxia or hemodynamic instability.
Do not reinsert the needle into an indwelling catheter; the needle can shear the plastic catheter.
Base contact is required unless the documented MCI, remote-rescue, or tactically unstable-scene exception applies.

Confirm the indication

Adult/adolescent: use needle thoracostomy for suspected tension pneumothorax when qualifying findings are associated with hypoxia or hemodynamic instability. Pediatric: use it for tension pneumothorax causing hemodynamic instability in a chest-injury patient.
Adult/adolescent findings can include blunt or penetrating chest injury, absent breath sounds on the suspected side with breath sounds present on the opposite side, distended neck veins, circulatory collapse, respiratory arrest, or progressive dyspnea.
Pediatric findings can include chest injury, unilateral absent breath sounds, progressive dyspnea or respiratory arrest, poor perfusion, and altered mental status.

Make base contact before decompression. In an MCI, remote rescue, or tactically unstable scene, proceed without base contact and document the circumstances.
Adult/adolescent: use a 3.25-inch ARS 10-gauge catheter-over-needle device or a minimum 2.5-inch 14-gauge catheter-over-needle device, plus antiseptic and a sterile occlusive dressing.
Pediatric: at an estimated weight of 40 kg or less, use a 1.25-inch 16-gauge catheter-over-needle device. Above 40 kg, use an adult decompression needle at least 2.5 inches long.

Explain the procedure when the patient is conscious and able to understand. Identify the second intercostal space at the midclavicular line and prepare the site.
At the lower aspect of the second intercostal space, insert perpendicular to the chest wall with steady pressure.
Advance until a rush of air, a pop or giving-way sensation, or air, blood, or fluid through the needle confirms entry into the chest cavity.
Adult/adolescent: remove the needle and leave the catheter in place. Pediatric: once the chest cavity is entered, advance the needle and catheter one-quarter inch and no farther, then remove the needle and leave the catheter.

Secure the catheter with sterile Vaseline gauze or an appropriate dressing and tape; in a pediatric patient, arrange the gauze at the catheter base to stabilize and seal the site.
Reassess respiratory status, perfusion, and hemodynamic status. Document the indication, base-contact status or exception, site, procedure, and response.